How are sexual identity biases processed in mind and brain? Does religious belief mediate such prejudice? Forty-five participants completed a version of the IAT in which images of heterosexual and homosexual couples were paired with positive and negative adjectives. Prior to each set of trials, participants were primed with four verses of either benevolently themed scripture or persecutory scripture. All participants were exposed to all conditions in counterbalanced orders. Additionally, electroencephalographic (EEG) measurements were recorded during the experiment, and event-related potentials (ERPs) extracted. Three post-experiment questionnaires were used to obtain personality measures of religious fundamentalism, quest, and explicit attitudes toward homosexuality. The results revealed a positive correlation between fundamentalism and enhanced implicit bias, as well as a negative correlation between enhanced bias and quest. As expected, there were significant differences between compatible and incompatible conditions for both altruistic and persecutory verse conditions. Interactions between religious fundamentalism and verse condition, explicit homosexual prejudice and verse condition, and quest and verse conditions in relation to implicit bias were also observed. This experiment explored the priming effects of religiosity on Implicit Association Test (IAT) performance and attempted to identify specific neural correlates of implicit bias via event-related potentials (ERPs). ERPs yielded N400, early positivity, and late positivity potential differences between high and low religious fundamentalism groups and high and low implicit bias groups. The ERP data revealed fundamentally different brain activity for highly religious participants compared to participants with low religiosity.